Field of the Invention
The invention relates to a method for parameterizing interlocking conditions for bay controllers and/or protective devices of a switching arrangement.
Interlocks to prevent maloperation play an important part in electrical switchgear. This protection ensures that switching devices are only switched when it is also admissible. In particular, it is intended to avoid switching of disconnectors under load, coupling of asynchronous power supply units, switching to equipment that is grounded or grounding of equipment that is under voltage. This means for example that a closed switch in one part of an electrical power supply system prevents tripping of a disconnector in another part of the electrical power supply system, which is known as “interlocking”. The dependence of the decision to enable switching or to interlock one specific switching device on the switching state of other switching devices is a result of the topology of the energy supply system. Within the scope of this patent application, the term interlocking conditions also includes enabling conditions.
It is intended for the switchgear interlocking to prevent defective or unwanted switching actions from causing harm to persons or damage to technical equipment. A distinction is made between safety-related decisions, which avoid a risk to people and equipment, and operation-related decisions, which essentially reflect the operating philosophy of an installation and restrict the safety-relevant enabling of switching actions. There may for example be an operating philosophy that, for reasons of overall clarity, maintains the switching sequence in such a way that a power circuit breaker is only closed when the corresponding disconnectors are closed. Further examples of aspects to be noted within an operating philosophy are tripping or transferring an outgoing unit to an additional auxiliary bus bar, coupling bus bars, ensuring a continuous power supply and maintaining the limits of withstanding a short circuit of the circuit breakers that are used.
It has been customary so far in the prior art to make the decisions for enabling switching or interlocking with the aid of Boolean equations. These equations must be individually configured for each installation, which in the case of relatively large installations is very complex and confusing. This increases the risk of erroneous or incomplete expressions and equations and associated safety risks.
For this reason, ideas for an automatic evaluation of the interconnection of switching devices, that is to say the topology of an electrical switchgear, have been developed in the prior art. With the aid of the topology, it is possible to automate at least partially the creation of interlocking conditions for the switching devices and thus reduce the configuration effort in the parameterization of the switching devices. It has generally been the practice here to consider an individual switching arrangement with multiple bays.
The interlocking of switching actions on the basis of topological information is treated in the dissertation entitlte “Ein universelles Verriegelungsverfahren auf topologischer Basis” [A Universal Interlocking Method on a Topological Basis] by Heinrich Hoppe-Oehl, submitted to Saarland University in 1991. It involves for example an evaluation of prescribed interlocking conditions being performed by means of a centralized interlocking device. A topology is detected on the basis of image recognition from a single-line overview (pages 36 and 37), interlocking patterns being detected on the basis of a pattern recognition by means of prescribed patterns and taken into account (pages 77-79 and 88).
Furthermore, the dissertation by Steffen Berthold at the University of Dresden (1992) “Der integrierte Schaltfehlerschutz sowie neue Verfahren zur Projektierung and Abarbeitung von Schaltverriegelung” [Integrated Switchgear Interlocking and New Methods for the Planning and Execution of Interlocking] is concerned with the interlocking of switching actions on the basis of topological information. In order to achieve operationally dependent interlocking conditions for switchgear, additional efforts have to be undertaken. It is mentioned that this concerns a pattern recognition that has to be evaluated for the interlocking. These patterns must however be defined in advance.
Furthermore, German patent application DE 38 12 072 C3 discloses the possibility of evaluating the topology of the interconnection of switching devices of a switch gear. Operationally dependent interlocking can be achieved by the safety-related interlocking conditions being extended with Boolean equations. It is assumed here that the operationally dependent and safety-related interlocking conditions are centrally determined and transferred into the individual switching devices during the planning of an installation.
Also known is the IEEE publication “Topology-Based Interlocking of Electrical Substations” by J. Kopainsky, W. Wimmer and K. P. Brand, appearing in “IEEE Transactions on Power Delivery”, July 1986, pages 118-126. In it, a method based on the topology of a switching arrangement is discussed. Both safety-related and operation-related interlocking conditions are based on pattern recognition for components of a topology, which is to say for example for a branch of a circuit.
It is also known from the product description “DIGSI 5, Software-Beschreibung” [DIGSI 5, Software Description], identification number C53000-D5000-0001-5, issue 10.2013, from Siemens AG, to use software to perform simplified planning and operation of all SIPROTEC 5 protective devices. Topologies of switchgear can be input, protective devices configured and corresponding communication networks between the devices planned essentially manually. This takes place offline, it then being possible for the parameterizations created to be transferred to the respective protective devices via a communication network. The topologies of switchgear are set up as a single-line representation and hardware and networks are added on a graphical basis (symbolically). With the function “Continuous Function Chart” (page 294 ff.), interlocking conditions can also be parameterized manually by the user, with Boolean equations being used.